Injection-type semiconductor laser

Abstract

A semiconductor laser having a double heterostructure configuration is provided with a light waveguide layer extending between a pair of mirrors. A thin active layer is disposed adjacent to the waveguide layer, and is formed in the shape of a stripe having a width of approximately 5 μm. The stripe is shorter in axial length than the waveguide, such that the ends of the stripe are spaced from the mirrors by a distance of 30 to 60 μm.

What is claimed is: 
     
       1. In a semiconductor laser having a multi-layer structure formed on a substrate and two opposing cleaved surfaces, said semiconductor laser comprising: a first semiconductor layer for guiding a laser beam;   an active layer disposed in contact with said first semiconductor layer, said active layer being formed in the shape of a stripe, said stripe having substantially planar ends which are spaced from said cleaved surfaces;   a third semiconductor layer burying said active stripe;   a first electrode for supplying a first electric potential through said third semiconductor layer; and   a second electrode formed on said substrate for supplying a second electric potential thereto.   
     
     
       2. A semiconductor laser as claimed in claim 1, wherein the width of said active layer stripe is approximately 5 μm. 
     
     
       3. A semiconductor laser as claimed in claim 1, wherein the ends of said active layer stripe are spaced from said mirrors by a distance of 30 to 60 μm. 
     
     
       4. A semiconductor laser as claimed in claim 1, wherein said third semiconductor layer has a conductivity type opposite that of said first semiconductor layer. 
     
     
       5. A semiconductor laser as claimed in claim 1, said third semiconductor layer having a first portion of a conductivity type opposite the conductivity type of said first semiconductor layer and being formed over said active layer, and having a second portion having the same conductivity type as said first semiconductor layer. 
     
     
       6. A semiconductor laser as claimed in claim 5, wherein an insulative film is formed over said second portion. 
     
     
       7. A semiconductor laser as claimed in claim 5, wherein said active layer is formed as a segmented stripe. 
     
     
       8. A semiconductor laser as claimed in claim 5, wherein the ends of said segmented stripe are spaced from said mirrors by a distance of 30 to 60 μm. 
     
     
       9. In a semiconductor laser having a multi-layer structure formed on a substrate and two opposing cleaved surfaces, said semiconductor laser comprising: a first semiconductor layer for guiding a laser beam;   an active layer disposed in contact with said first semiconductor layer, said active layer being formed in the shape of a segmented stripe, said segmented stripe at both ends having substantially planar ends which are spaced from said cleaved surfaces;   a third semiconductor layer of a first conductivity type formed between adjacent portions of said segmented stripe and between each of said cleaved surfaces and said segmented stripe at both ends thereof;   a fourth semiconductor layer of the opposite conductivity type with respect to said first conductivity type formed in contact with said segmented stripe;   an insulating layer covering said third semiconductor layer;   a first electrode for supplying an electric potential through said fourth semiconductor layer; and   a second electrode formed on said substrate for supplying a second electric potential thereto.   
     
     
       10. A semiconductor laser as claimed in claim 9, wherein the distances between said adjacent portions of said segmented stripe are constant.